This invention relates to a recording/playback head assembly for use in a magneto-optic memory device wherein light beam such as a laser beam is applied to a magneto-optic memory medium having its easy axis of magnetiziation lying in a direction perpendicular to the medium plane to increase the temperature of a laser-affected portion and reduce retentiveness at that portion and magnetic domains are aligned along a magnetic field working at that portion for recording and erasure of information and a magneto-optic effect is relied upon for playback of information.
In recent years, a substantial amount of effort has been directed toward the development of an optical memory medium which satisfies various requirements including high density, large capacity and high speed access. Various optical memory systems have been put into practical use: for example, a system where a plurality of arrays of minute pits are formed in a memory disc and playback is carried out through the utilization of light beam diffraction taking place at those pits and a system where playback is effected using variations in reflection factor. However, those systems are capable only of reproducing information or recording additional information. An optical memory system which has capability of erasing information is still in the stage of research and development.